Use of a Ginkgo Complexes for the Enhancement of Cognitive Functions and the Alleviation of Mental Fatigue

ABSTRACT

The invention is directed to the use of Ginkgo complexed with phosphatidylserine for the manufacture of a medicament or a dietary supplement for the enhancement of cognitive function and mental fatigue, i.e. to improve the factors related therewith such as to improve the speed of memory and memory quality, to increase accuracy and attention in activities in normal, healthy subjects, to prevent deterioration of the speed and quality of memory in people with decreased cognitive functions and to counteract cognitive fatigue, having also an influence on the mood, particularly in healthy children, young adults, middle-aged and/or old people. It is further provided the use of the Ginkgo phosphatidylserine complex for the treatment and prevention of a disease related with a decrease of the cognitive function and mental fatigue such as Dementia, e.g. Alzheimer&#39;s Disease.

FIELD OF THE INVENTION

The present invention relates to a novel use of a Ginkgo complex for theenhancement of cognitive function and mental fatigue functions.

BACKGROUND OF THE INVENTION

The isolation of a lactone compound C₁₅H₁₈O₈ from the leaves of Ginkgobiloba, to which the name bilobalide was given, was first mentioned in1967 by R. T. Major (Science 157 (1967), p. 1270-1273). The structuralformula for said bilobalide was already proposed in 1971 (J. Amer. Chem.Soc. 93 (1971), p. 3544-3546) and is as follows:

The active main components of Ginkgo are alkylated phenoles such asginkgol and 3-(8-pentadecenyl) phenol, and phenolic carboxylic acidssuch as 2-hydroxy-6-(8-pentadecenyl) benzoic acid, ginkolide andbilobalide. Bilobalide, a sesquiterpene, and ginkgolide, a hexacyclicditerpene, are the only known naturally occurring compounds having tert.butyl groups. Said substances may be isolated from the leaves and otherorgans of the Ginkgo biloba tree, e.g. bilobalide is found in the leavesof Ginkgo biloba at concentrations below 0.01%.

The known extracts have been used for the treatment of disturbances ofcerebral and peripheral arterial blood flow. The containedginkgo-flavone glycosides and terpenoids are known to havevaso-regulating and blood viscosity decreasing properties. The mainindications for which Ginkgo is prescribed in Western countries, such asFrance and Germany, is cerebral insufficiency. Further, Ginkgo bilobahas been extensively used for various indications in Chinese medicineand is described in the traditional Chinese Pharmacy.

In recent years also complexes between natural or syntheticphospholipids and bilobalide, as well as preparations thereof, have beeninvestigated. The U.S. Pat. No. 5,043,323, for example, disclosescomplex compounds of bioflavonoids with phospholipids, including Ginkgobiloba complexed with phosphatidyl serine.

Furthermore, the U.S. Pat. No. 5,202,313 suggests their therapeuticapplication as antiinflammatory agents and as agents for the treatmentof disorders associated with inflammatory or traumatic neuriticprocesses.

Moreover Ginkgo extracts are known to have effects on cognitivefunctions. For example V. D. Petkov et al., Planta Med. 59 (1993), pp.106-114, disclose that the standardized extracts of Panax ginseng,Ginkgo biloba and a combination thereof improve the learned behavior ofyoung and old rodents.

According to the teaching of WO 01/43753 A2 it was found in cognitivetests that administering a combination of extracts of the root of Panaxginseng and of the leaves of Ginkgo biloba to humans positively effectscognitive skills, for example the speed and quality of memory in normalhealthy subjects.

Furthermore, there has been a variety of studies on the influence ofginkgo biloba extract on cognitive performance. It has been suggested(Moss and Scholey 1996, Scholey et al 1999, Kennedy and Scholey 2000)that some demanding cognitive tasks may be facilitated by the simpleaugmentation of delivery of metabolic substrates to the brain. As anexample, a previous study from this laboratory (Kennedy and Scholey2000) investigated the relationship between heart rate, blood glucoselevels and performance on a “demanding” mental arithmetic task (serialverbal subtraction of 7 from a given number between 800 and 1000), a“less demanding” mental arithmetic task (serial subtraction of 3), and along term verbal memory task. It was found that not only both serialsubtraction tasks engendered significant increases in heart rate abovethat engendered by somatically identical counting tasks, but thatperformance on both was also related to the magnitude of fall in bloodglucose levels during task performance. Performance on the mostdemanding task (serial 7s) was also not only improved by a glucosedrink, but was also related to resting heart rate.

However the effects according to the use of the inventive complex aresuperior and of a novel type.

SUMMARY OF THE INVENTION

Unexpectedly, it has been found by the present inventors that a Ginkgobiloba extract complexed with phosphatidyl serine may be used to enhancesignificantly above the levels provided by the non-complexed extractcognitive function and mental fatigue, which comprises theadministration of a medicament and/or a dietary supplement containingGinkgo in the complexed form. The Ginkgo complex may be used for theenhancement of cognitive function and mental fatigue in healthy people,in particular children or young adults.

Another aspect of the present invention is the possibility to preventdeterioration of the speed of memory in people with decreased cognitivefunctions and to counteract cognitive fatigue.

A further aspect of the present invention is the maintenance of healthycognitive functions and delay of age-related cognitive decline inmiddle-aged and/or old people, particularly healthy middle-aged and/orhealthy old people.

Still another aspect of the present invention is the possibility ofproviding a medicament or a dietary supplement for the treatment andprevention of a disease related with a decrease of the cognitivefunction and mental fatigue such as Dementia, e.g. Alzheimer's disease.

It is therefore a primary object of the present invention to provide theuse of an active composition to enhance the cognitive function andmental fatigue, i.e. to improve the factors related therewith such as toimprove the speed of memory and memory quality, to increase accuracy andattention in activities in normal, healthy subjects, to preventdeterioration of the speed and quality of memory in people withdecreased cognitive functions and to counteract cognitive fatigue, alsohaving an influence on the mood, particularly in healthy children, youngadults, middle-aged and/or old people.

It is a further object of the present invention to provide the use of anactive composition for improving cognitive skills and/or mental effortby taking formulations comprising ingredients of natural origin, whereinthe constituents are manufactured pursuant to a controlled process thatpreserves the curing qualities of the ingredients.

It is still a further object of the present invention to provide the useof an active composition comprising constituents of natural origin andhaving minimal or no side effects and thus being safe for internalconsumption.

It is a further object of the present invention to provide the use of anactive composition for the treatment and prevention of a disease relatedwith a decrease of the cognitive function and mental fatigue such asDementia, e.g. Alzheimer's disease.

Furthermore, the invention relates to a pharmaceutical or dietarycomposition comprising a Ginkgo biloba extract complexed withphosphatidyl serine, at least one vitamin, optionally one or moreminerals and trace elements and a pharmaceutically or dietarilyacceptable carrier.

Finally, the invention relates to a Ginkgo biloba extract complexed witha certain phosphatidyl serine with a defined ratio of different fattyacids.

DESCRIPTION OF THE INVENTION

The present invention refers to the use of Ginkgo complexed withphosphatidylserine for the manufacture of a medicament or dietarysupplement for the enhancement of cognitive function and mental fatigue.The Ginkgo used is derived from the plant Ginkgo biloba, and representsan extract or extracts thereof and/or the principal active substancesthereof.

Under the term Ginkgo phosphatidylserine complex or abbreviatedGinkgo-PS is meant a complex obtainable from a reaction of the activeingredients of an extract of Ginkgo with a phospholipid containing from10 to 50%, preferably from 20 to 40%, more preferably 20% ofphosphatidylserine.

Under the term “extract” is meant that the plants or plant componentsare extracted with a suitable solvent like water, ethanol, a mixturethereof, oils or any other suitable solvent well known in the state ofthe art of extracting plants. These extracts can be used as such ifpharmacologically acceptable or the solvent of the resulting solutionsis removed and the residue is used as such or after further worked up,for example after resolving or re-suspending in a pharmacologicallysuitable solvent.

Under the term “principal active substances” is meant the activeingredients that are mainly responsible for the pharmacological effect.Preferably the formulation comprises all those ingredients of the plantof interest that are responsible for at least about 75 percent, morepreferably at least about 90 percent of the pharmacological effects.These active ingredients may be won from the plants or synthesizedchemically.

As used herein a “pharmacologically acceptable” component is one that issuitable for use with humans without undue adverse side effects such astoxicity, irritation and allergic response, commensurate with areasonable benefit/risk ratio.

Complexes between natural or synthetic phospholipids and bilobalide areknown from prior art (e.g. U.S. Pat. No. 5,043,323 and U.S. Pat. No.5,202,313), as well as the preparation thereof and their therapeuticapplication as anti-inflammatory agents and as agents for the treatmentof disorders associated with inflammatory or traumatic neuriticprocesses. Bilobalide forms with phospholipids new compounds, whichexhibit a different bioavailability compared with free bilobalide andare suitable for incorporation into pharmaceutical formulations.

The complex between the flavonoids from Ginkgo biloba andphophatidylserine is prepared analogously as described in examples 6 ofU.S. Pat. No. 5,043,323.

Preparation of Ginkgo biloba extract soy phosphatidylserine complex.1.87 kg of 20% phosphatidylserine were suspended at room temperature in17.5 L of ethyl acetate. Ginkgo biloba dry extract (0.65 kg) was addedand stirring. The suspension was kept under stirring at reflux for 1hour.

The suspension was filtered at 70-75° C. and the mother liquorsconcentrated at ambient pressure until a soft residue is obtained.

The residue was dried at 40° C. for 48 hours. Yields: 2.23 kg of Ginkgobiloba extract phosphatidylserine complex.

Therefore, the formation of Ginkgo phospholipid complexes enables thepreparation of new biologically active compositions. In fact, theypossess physico-chemical and spectroscopic characteristics which aremarkedly different from those of the original components and as suchthey can be incorporated as active principles into pharmaceuticalformulations. Ginkgo shows a strong affinity for phospholipids,resulting in the generation of bonds which markedly modify thephysico-chemical and spectroscopic characteristics of the new molecules.The formation of the complex will be confirmed for example by nuclearmagnetic resonance analysis, which enables the identification of theinteraction between the reacting molecular species and the portion ofthe molecule which is involved in the reaction.

Specifically, the complex of the present invention comprises herbalingredients for example derived by an extraction from Ginkgo leaves. TheGinkgo extract contains among other substances ginkgo flavone glycosidesand terpene lactones. Another possibility is that the formulationcomprises dried Ginkgo leaves or other plant components, that optionallyare powdered. Under the term “plant” is understood the plant itself aswell as plant parts comprising the active ingredients. Like for exampleleaves, stems, fruits or roots as mentioned above. Preferably the plantor plant components are dried. Optionally, they may be powdered.

While all these substances present in Ginkgo are known to havepharmacological activities, the range of their pharmacological actionshas not yet been fully elucidated, but in-vitro studies indicate thatsome of them have antioxidant properties and that they inhibit plateletaggregation, while others exert an action on the oxygen uptake in thecells and others again may exert an immunomodulating action.

In a preferred embodiment the Ginkgo extract used contains among othersubstances ginkgo flavone glycosides and terpene lactones, preferablycontaining at least about 20%, preferably about 21.0 to about 30%, inparticular about 22.0 to about 27.0% ginkgo flavone glycosides and about2 to about 10%, preferably about 4.0 to about 8.0%, in particular about5.0 to about 7.0%, most preferably about 6% terpene lactones. Preferablythe medicament and/or dietary supplement comprises Ginkgo extractcontaining at least about 24% ginkgo flavone glycosides and about 6%terpene lactones. In particular Ginkgo extract disclosed in EP 0360556is used as basis to produce the complex.

The phospholipids used for the preparation of the complexes may beeither natural or synthetic. The natural phospholipids are normallythose extracted from soy-bean or from animal organs, whereas thesynthetic phospholipids have homogeneous acyl chains and are preparedaccording to methods described in prior art.

According to the present invention the phospholipid selected for thepreparation of the complex is a phospholipid containing from 10 to 50%of phosphatidylserine. Preferably the phospholipid contain from 20 to40% and particular preferred about 20% of phosphatidylserine of formula

wherein

R and R¹ each independently represent an C₆₋₂₀ acyl group, preferably anacyl moiety selected from the group consisting of palmitoyl, oleoyl,linoleoyl, linolenoyl, in particular which comprises, on an average,from 15 to 25% of saturated fatty acids, from 5 to 15% ofmono-unsaturated fatty acids and from 60 to 80% of polyunsaturated fattyacids, based on the total acids; and

R² represents the residue of serine.

The reaction of Ginkgo with phosphatidylserine under appropriateconditions results in the generation of a product whose physico-chemicalcharacteristics are completely different from those of the individualconstituents.

The resulting complex is lipophilic in character and is soluble innonpolar and aprotic solvents, in which the individual components of thecomplex are normally insoluble.

The resulting complex exhibits a greater activity as compared to Ginkgoin free form and are suitable for incorporation into the most commonpharmaceutical formulations.

The complexes described in the present invention may be prepared byreacting in proper solvents, such as hot cyclic ether, aromatichydrocarbons, halogen derivatives or methanol-methylene chloridemixture. It is therefore preferred that the ratio between Ginkgo and thephospholipid used to prepare the complex is about 0.5-1:2-5, preferably1:3 W/w. The final products are then isolated by evaporation of thereaction solvent or by precipitation of the complex with appropriatesolvents. The complex may also be prepared by lyophilizing the productobtained from the reaction of the components in dioxane.

The production of the complex used according to the present inventionprovides a useful mode of administration for Ginkgo, the principalactive substances or extracts thereof. The possibility of producing newstructures with Ginkgo extracts which retain unaltered the structure ofthe basic compound but exhibit a several-fold increase in a specificactivity represents a significant advantage for the novel use whichcertainly could not be predicted beforehand. Due to the enhancement inthe specific activity used, it is possible to reduce the dosage havingthe known benefits.

It has been unexpectedly found that the complex used according to thepresent invention has a direct influence on the cognitive function andmental fatigue. The expression “cognitive performance” involves but isnot limited to improve factors related therewith such as improved speedof memory and memory quality, improved reaction time and working memory,increased accuracy and attention in activities in normal, healthysubjects, to prevent deterioration of the speed and quality of memory inpeople with decreased cognitive functions and to counteract cognitivefatigue having an influence on the mood and the physical well-being,particularly in healthy children, young adults, middle-aged and/or oldpeople. It could be demonstrated that the ginkgo phosphatidylserinecomplex used according to the present invention has an excellentinfluence and effectivity on cognitive function and mental fatigue andthe related cognitive factors such as quality of memory, speed ofmemory, and the majority of the activities concerning attention andaccuracy. The general context will be clear from the study explained inthe experimental part.

The complex can be used at dosages ranging from about 20 to about 240mg/day, preferably about 60 to about 120 mg/day, particularly preferredfrom about 80 to about 100 mg/day in single or divided dailyadministrations as medicament or as a dietary supplement.

The medicament or dietary supplement may be in the form of tablets,coated tablets, granules, powders, powders in capsules, syrups,solutions or suspensions for example on the basis of water, ethanol or amixture thereof, dragees, gels, injections or any other suitable mannerwell known to the skilled person. These products may be administeredalso as topical formulations, at variable dosages depending on thedesired application, e.g. the severity of the pathological conditionbeing treated. Preferably, the medicament and/or dietary supplement isadministrated in a form suitable for oral administration, such asgranules, tablets, capsules, drops, syrups or others.

The term “dietary supplement” as used hereinabove and hereinbelowincludes a composition which may be used without prescription by a thirdparty, for example a physician. The components may be taken togetherwith meals or separated thereof, on a daily basis or only sometimes.Dietary supplements are primarily important for those having inadequatediets, individuals with a reduced ability to utilize or absorb theessential substances from food, particularly the elderly persons.

According to a preferred embodiment of the present invention the Ginkgophosphatidylserine complex may be used with a suitable orpharmacologically acceptable amount of additives. Such additives may be,but are not limited to minerals, vitamins, sweeteners, flavors,pharmaceutically acceptable carriers, auxiliary and binder agents,excipients and mixtures thereof.

The minerals used may be for example selected from salts of calcium,copper, magnesium, iron, zinc, iodine, selenium, manganese, fluoride,chromium, molybdenum, sodium, potassium, chloride and mixtures thereof.Additional minerals which are less preferred are arsenic, nickel,silicon, boron, cadmium, lead, lithium, tin, vanadium and cobalt saltsand mixtures thereof. The mineral sources are usually present innutritionally relevant amounts. The source of the mineral salts usedmaybe any of the well known salts such as carbonate, oxide, hydroxide,chloride, sulfate, phosphate, gluconate, lactate, acetate, fumarate,citrate, malate, amino acids and the like for the cationic minerals andsodium, potassium, calcium, magnesium and the like for the anionicminerals. Those skilled in the art are familiar with the preferredranges for infants or adults, depending somewhat on age andphysiological state. It is clear that the daily intake of minerals mayvary with the user so that no exact dosages may be mentioned. Accordingto the present invention it is most preferred that the followingminerals present in the medicament or dietary supplement may be selectedfrom calcium, fluorine, phosphorus, copper, potassium, manganese,magnesium selenium, zinc and iron.

Vitamins which may optionally be used according to the present inventioncan be, but are not limited to water-soluble vitamins e.g. Vitamin Ce.g. L-(+)-ascorbic acid, calcium ascorbate, potassium ascorbate,6-palmitoyl-L-ascorbic acid; Vitamin B1 e.g. thiamine hydrochloride,thiamine mononitrate; Vitamin B2 e.g. riboflavin, riboflavin5′-phosphate sodium; Vitamin B6 e.g. pyridoxine hydrochloride, VitaminB12 e.g. cyanocobalamine; Vitamin H e.g. D-biotin; Folic Acid; VitaminPP (Niacin) e.g. nicotinamide, nicotinic acid; pro Vitamin B5 e.g.panthenol (d and d1 forms) ethyl panthenol and calcium D-pantothenate;and fat-soluble vitamins e.g. Vitamin A e.g. Vitamin A palmitate,Vitamin A acetate, Vitamin A propionate, all trans retinol; Vitamin De.g. ergocalciferol, cholecalciferol, cholecalciferol-cholesterol;Vitamin E e.g. alpha-tocopherol, alpha-tocopheryl acetate,alpha-tocopheryl acid succinate (d and dl forms); Vitamin K such VitaminK1 e.g. phytomenadione, and Carotene (provitamin) e.g. lycopene,zeaxanthin, lutein, alpha-carotene, beta-carotene, apocarotinal,gamma-carotene and beta-cryptoxanthin, derivatives and mixtures thereof.The vitamins may be present in nutritional relevant amounts depending onage and physiological state as already mentioned above. Preferredvitamins are vitamin A, vitamins B1, B2 and B12, vitamin C, vitamin D2,nicotinamide, calcium pantotenate, rutoside and vitamin E.

Further additives in medicaments or dietary supplements which mayoptionally be present belong to basic knowledge of the skilled personand shall not be discussed in detail.

According to the present invention it is particularly preferred ifminerals and/or vitamins are present as additives. Such a combination ofthe Ginkgo phosphatidylserine complex and selected multivitamins and/orminerals is particularly suitable for maintaining and/or restoringcognitive functions and improving physical well-being, for example inelderly persons or patients. Thus, the Ginkgo complex combined with amultivitamin/minerals formulation may be tailored particularly to theneeds of elderly persons who face or want to prevent age-related declineof cognitive functions and physical well-being. It is a meaningfulcombination of Ginkgo and phosphatidylserine in form of a complex whichis proven in the experimental part to have strong beneficial effects oncognitive function. The performance may be increased with additives suchas minerals and/or vitamins which are selected and dosed according totheir potential of maintaining and restoring cognitive functions andimproving physical well-being, particularly of elderly persons. Mostpreferred is a combination consisting essentially of:

-   -   a complex of Ginkgo extract and phosphatidylserine    -   Vitamin A    -   Vitamin B1    -   Vitamin B2    -   Vitamin B6    -   Vitamin B12    -   Vitamin C    -   Vitamin D2    -   Vitamin E    -   Nicotinamide    -   Calcium Pantotenate    -   Rutoside    -   Folic Acid    -   Fluorine    -   Calcium    -   Phosphorus    -   Copper    -   Potassium    -   Manganese    -   Magnesium    -   Zinc    -   Iron    -   Lecithin

Therefore, the complex according to the present invention may be usedfor the improvement of cognitive functions in healthy young people andthe maintenance of healthy cognitive functions and delay of age-relatedcognitive decline in healthy middle-aged and/or old people. However,according to a further embodiment the complex may be used formanufacturing a medicament or a dietary supplement for the treatment andprevention of diseases related with the reduction of cognitive functionand mental fatigue.

Still a further aspect of the present invention is directed to the useof Ginkgo complexed with phosphatidylserine for the manufacture of amedicament or a dietary supplement for the treatment and prevention ofDementia, e.g. Alzheimer's disease.

It is preferred that the medicament or dietary supplement additionallycontains a pharmaceutically acceptable amount of at least one additivewhich may be selected from the group comprising vitamins, minerals,sweeteners, flavors, pharmaceutically acceptable carriers, auxiliary andbinder agents, excipients and mixtures thereof, as already described.

In a preferred embodiment the complex of the present invention may alsobe used in combination with an additionally active compound, i.e. theGinkgo complex may also play a role in the combination treatment ofDementia such as age-related Dementia, e.g. Alzheimer's Disease. Anactive compound in this connection may be a pharmaceutical compound oranother active substance used for the treatment and prevention of thedisease to be treated, e.g. a compound which supports the treatment andcuring of Alzheimer's Disease.

One example of said embodiment of the invention may be to use Ginkgocomplexed with phosphatidylserine of the invention as adjuvant therapyin the treatment of Dementia particularly Alzheimer's disease incombination with acetylcholinesterase inhibitors. The leadingacetylcholinesterase inhibitors in the treatment of Dementia areDonepezil (Aricept® available from Pfizer), Rivastigmine (Exelon®available from Novartis) and Galantamine (Reminyle available fromJohnson & Johnson). Therefore the complex of the present invention maybe co-administered with such a known acetylcholinesterase inhibitor. Inthis context under the term “co-administration” is meant that each ofthe two components (complex and additional active compound) areadministered at the same time or separately but within a close timelyrelationship.

A further embodiment for the combined therapy with the inventive complexand an additionally active compound is the combination treatment in anage-related Dementia such as Alzheimer's Disease by theco-administration of the complex of the present invention and complexedgrape seed extract as additionally active compound. It has been foundthat the combined use of the inventive complex and an additionallyactive compound leads to superior results in the prevention or curing ofsuch diseases and supports to alleviate the symptoms and to extenuatethe course of the disease in an extraordinary way.

DETAILED DESCRIPTION OF THE INVENTION

In a pilot study in form of a randomised, double-blind, balancedcrossover study the influence of several preparations on cognitiveskills was conducted. In this study, the effects and influence of aginkgo phosphatidylcholine complex, ginkgo phosphatidylserine complex,not complexed ginkgo and an inert placebo have been compared andevaluated.

It will be readily apparent to those skilled in the art that variouschanges and modifications of an obvious nature may be made withoutdeparting from the spirit of the invention, and all such changes andmodifications of an obvious nature may be made without departing fromthe spirit of the invention, and all such changes and modifications areconsidered to fall within the scope of the invention, as defined by theclaims. While the use of the complex of the present invention has beenset forth in what is believed to be preferred embodiments, it isrecognized that departures may be made within the spirit and scope ofthe following claims which, therefore, should not be limited exceptwithin the doctrine of equivalents.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows the effects of individual tasks with regard to attention;

FIG. 2 shows the effects on speed of memory;

FIG. 3 shows the effects on timed memory tasks;

FIG. 4 shows the effects on quality of memory;

FIGS. 5 shows the effects on picture recognition accuracy; and

FIG. 6 shows and the effects found on mood “calm”.

METHOD Cognitive Assessment Participants

19 female and 9 male undergraduate volunteers (mean age 21.4 years,Standard Deviation 4.1 years) took part in the study which was approvedby the Joint Ethics Committee of Newcastle and North Tyneside HealthAuthority and was carried out in accordance with the Declaration ofHelsinki. Prior to participation each volunteer signed an informedconsent form and completed a medical health questionnaire. Allparticipants reported that they were in good health, and were taking noillicit social drugs. Additionally they were free of any “over thecounter” or prescribed medications, with the exception, for some femalevolunteers, of the contraceptive pill. Regular smokers were excludedfrom the study. All participants abstained from alcohol for a minimum of12 hours prior to the first testing session of the morning.

Cognitive Drug Research (CDR) Computerised Assessment Battery

The Cognitive Drug Research (CDR) computerised assessment battery hasbeen used in hundreds of European and North American drug trials, andhas been shown to be sensitive to acute cognitive improvements (e.g.Moss et al 1998; Scholey et al 1999) as well as impairments with a widevariety of substances (e.g. Ebert et al 1998; O'Neill et al 1995).

A tailored version of the CDR battery was used. This has previously beenfound to be sensitive to modulation of cognitive function as aconsequence of acute ingestion of Melissa officinalis Kennedy et al,2002b), Ginkgo biloba (Kennedy et al 2000; 2002a) and Panax ginseng(Kennedy et al 2001a; 2002a), and acute and chronic administration of aGinkgo biloba/Panax ginseng combination (Kennedy et al 2001 b; 2002a;Wesnes et al 1997; Wesnes et al 2000). In the case of the current studythe additional rapid visual information processing (RVIP) task wasincluded in the battery. The selection of computer controlled tasks fromthe system was administered with randomly ordered parallel forms of thetests being presented at each testing session. Presentation was viadesktop computers with high resolution VGA colour monitors, and, withthe exception of written word recall tests, all responses were recordedvia two-button (YES/NO) response boxes. The entire selection of taskstook approximately 20 minutes to perform.

Tests were administered in the following order:

Word Presentation: Fifteen words, matched for frequency andconcreteness, were presented in random order on the monitor for theparticipant to remember. Stimulus duration was 1 second, as was theinterstimulus interval.

Immediate Word Recall: The participant was allowed 60 seconds to writedown as many of the words as possible. The task was scored as number ofwords correct and the resulting score was converted into a percentage.

Picture Presentation: A series of 20 photographic images of everydayobjects and scenes were presented on the monitor at the rate of 1 every3 seconds, with a stimulus duration of 1 second, for the participant toremember.

Simple Reaction Time: The participant was instructed to press the “YES”response button as quickly as possible every time the word “YES” waspresented on the monitor. Fifty stimuli were presented with aninter-stimulus interval that varied randomly between 1 and 3.5 seconds.Reaction times were recorded in msecs.

Digit Vigilance Task: A target digit was randomly selected andconstantly displayed to the right of the monitor screen. A series ofdigits was presented in the centre of the screen at the rate of 80 perminute and the participant was required to press the “YES” button asquickly as possible every time the digit in the series matched thetarget digit. The task lasted one minute and there were 15stimulus-target matches. Task measures were accuracy (%), reaction time(msecs) and number of false alarms.

Choice Reaction Time: Either the word “NO” or the word “YES” waspresented on the monitor and the participant was required to press thecorresponding button as quickly as possible. There were 50 trials, ofwhich the stimulus word was chosen randomly with equal probability, witha randomly varying inter-stimulus interval of between 1 and 3.5 seconds.Reaction times (msec) and accuracy (%) were recorded.

Spatial Working Memory: A pictorial representation of a house waspresented on the screen with four of its nine windows lit. Theparticipant was instructed to memorise the position of the illuminatedwindows. In 36 subsequent presentations of the house, one of the windowswas illuminated and the participant decided whether or not this matchedone of the lighted windows in the original presentation. The participantmade their response by pressing the “YES” or “NO” response button asquickly as possible. Mean reaction times were measured in msec, andaccuracy of responses to both original and novel (distractor) stimuliwere recorded as percentages which were used to derive a “% greater thanchance performance” score (percentage of original targets+percentage ofnovel targets correctly identified—100).

Numeric Working Memory: Five digits were presented sequentially for theparticipant to hold in memory. This was followed by a series of 30 probedigits for each of which the participant decided whether or not it hadbeen in the original series and pressed the “YES” or “NO” responsebutton as appropriate as quickly as possible. This was repeated twofurther times with different stimuli and probe digits. Mean reactiontimes were measured in msec, and accuracy of responses to both originaland novel (distractor) stimuli were recorded as percentages which wereused to derive a “% greater than chance performance” score as above.

Delayed Word Recall: The participant was again given 60 seconds to writedown as many of the words as possible. The task was scored for number ofwords correct and the resulting score was converted into a percentage.

Delayed Word Recognition: The original words plus 15 distractor wordswere presented one at a time in a randomised order. For each word theparticipant indicated whether or not he recognised it as being includedin the original list of words by pressing the “YES” or “NO” button asappropriate and as quickly as possible. Mean reaction times weremeasured in msec, and accuracy of responses to both original and novel(distractor) stimuli were recorded as percentages which were used toderive a “% greater than chance performance” score as above.

Delayed Picture Recognition: The original pictures plus 20 distractorpictures were presented one at a time in a randomised order. For eachpicture participants indicated whether or not it was recognised as beingfrom the original series by pressing the “YES” or “NO” button asappropriate and as quickly as possible. Mean reaction times weremeasured in msec, and accuracy of responses to both original and novel(distractor) stimuli were recorded as percentages which were used toderive a “% greater than chance performance” score as above.

Primary cognitive outcome measures The above measures were collapsedinto the “Quality of Memory” measure and five cognitive outcome factorsderived from the battery by a factor analysis conducted by Wesnes et al(2000). These measures have been utilised in a number of studies,including a several assessing the cognitive effects of herbal remedies(Kennedy et al, 2000; 2001a; 2001b; 2002a; 2002b; Wesnes et al, 1997;2000). The original factor analysis of data from the battery isdescribed in detail in Wesnes et al (2000).

Attention

“Speed of Attention” factor: derived by combining the reaction times ofthe three attentional tasks—simple reaction time, choice reaction timeand digit vigilance (units are summed milliseconds for the 3 tasks).

“Accuracy of Attention” factor: derived by calculating the combinedpercentage accuracy across the choice reaction time and digit vigilancetasks with adjustment for false alarms from the latter test. 100%accuracy across the two tasks would generate a maximum score of 100.

Memory

“Speed of Memory” factor: derived by combining the reaction times of thefour computerised memory tasks—numeric working memory, spatial memory,delayed word recognition, and delayed picture recognition (units aresummed milliseconds for the 4 tasks).

“Quality of Memory” measure: derived by combining the “Secondary Memory”and “Working Memory” factor scores (see below).

“Secondary Memory” factor: derived by combining the percentage accuracyscores (adjusted for proportions of novel and original stimuli whereappropriate) from all of the secondary memory tests—delayed wordrecognition, delayed picture recognition, immediate word recall anddelayed word recall (with adjustments to the total % correct for errorsand intrusions on the latter two tasks). One hundred percent accuracyacross the four tasks would generate a maximum score of 400 on thisindex.

“Working Memory” factor: derived by combining the percentage accuracyscores from the two working memory tests—spatial working memory, andnumeric working memory. One hundred percent accuracy across the twotasks would generate a maximum score of 200 on this index.

Serial 3s and 7s Subtraction Tasks A modified computerised version ofthe Serial Sevens test was utilised. The original verbal Serial Sevenstest (Hayman, 1942) has appeared in a number of forms, including as partof the Mini-Mental State Examination (Folstein et al, 1975). It has beenused to assess cognitive impairment during hypoglycaemia (e.g. Hale etal, 1982; Taylor and Rachman, 1988), and has also been used toinvestigate the relationship between increased blood glucose levels andcognitive performance (Kennedy and Scholey, 2000; Scholey et al, 2001;Scholey, 2001). In the current studies, computerised versions of serialsubtractions were implemented (see Scholey et al, 2001 for details),here using tests of 2 minutes duration. For the Serial Sevens task astandard instruction screen informed the participant to count backwardsin sevens from the given number, as quickly and accurately as possible,using the numeric keypad to enter each response. Participants were alsoinstructed verbally that if they were to make a mistake they shouldcarry on subtracting from the new incorrect number. A random startingnumber between 800 and 999 was presented on the computer screen, whichwas cleared by the entry of the first response. Each three-digitresponse was entered via the numeric keypad with each digit beingrepresented on screen by an asterisk. Pressing the enter key signalledthe end of each response and cleared the three asterisks from thescreen. The task was scored for total number of subtraction and numberof errors. In the case of incorrect responses, subsequent responses werescored as positive if they were correct in relation to the new number.

The Serial Threes task was identical to Serial Sevens, except that itinvolved serial subtraction of threes.

Subjective mood measure

The Bond-Lader Visual Analogue Scales (Bond and Lader 1974), consistingof 16 100mm visual analogue scales anchored by antonyms (e.g.Alert-Drowsy, Lethargic-Energetic, etc) were combined as recommended bythe authors to form three mood factors: alertness, calmness andcontentedness.

Treatments

On each study day participants received two capsules that were ofidentical appearance on each occasion. The individual capsules containedeither an inert placebo, 60 mg Ginkgo biloba extract, 180 mg of Ginkgobiloba extract complexed with phosphatidylcholine (equivalent to 60 mgof Ginkgo biloba extract, in the following referred to as “PC”), or 240mg of Ginkgo biloba extract complexed with phosphatidylserine(phospholipid containing 20% of phospatidylserine. The complex isequivalent to 60 mg of Ginkgo biloba extract and in the following isreferred to as “PS”). Depending on the condition to which theparticipant was allocated on that particular day the combination ofcapsules corresponded to a dose of either 0 mg (placebo), 120 mg ginkgo,360 mg ginkgo complexed with phosphatidylcholine, or 480 mg ginkgocomplexed with phospholipid containing 20% of phosphatidylserine. Tomaintain the double blind, coded treatments were provided by themanufacturer in identical hard gelatine capsules. A disinterested thirdparty was then responsible for preparing treatments as per the study'sLatin Square. The code remained unbroken until initial statisticalanalysis had been completed. All treatments were identical in appearanceand scent.

Procedure

Each participant was required to attend a total of five study days thatwere conducted seven days apart, to ensure a sufficient wash-out betweenconditions. Testing took place, commencing at the same time on each day,in a suite of laboratories with participants visually isolated from eachother.

On arrival at their first session on the first day participants wererandomly allocated to a treatment regime using a Latin Square designwhich counterbalanced the order of treatments across the four activedays of the study.

The first day was identical to the following four, except that notreatment (active or placebo) was offered, to allow familiarisation withthe test battery and procedure. Data from the four sessions of thispractice day were not included in any analysis. Each active study daycomprised four identical testing sessions. The first was a pre-dosetesting session which established baseline performance for that day, andwas immediately followed by the day's treatment on days 2 to 5. Furthertesting sessions began at 1 hour, 3 hours, and 6 hours followingconsumption of the day's treatment.

Each testing session comprised completion of the Bond-Lader visualanalogue scales, and the CDR test battery.

Statistics

Scores on the individual task outcomes, the four primary factors aridthe two memory sub-factors were analysed as “change from baseline” usingthe Minitab statistical package.

Prior to carrying out planned comparisons, an ANOVA (General LinearModel), with terms fitted to the model for dose, visit, dose x visit andsubject (Kirk 1968), was carried out to identify main effects andinteraction effects on change from baseline data for each measure. Theprimary statistical analysis of the “change from baseline” data for eachmeasure was carried out using planned comparisons, utilising t testswith the mean squares for “Dose*Time*Subjects” from an omnibus ANOVA asan error term (Keppel 1991). At each time point (1, 2.5, 4 and 6 hourspost-dose) data from the placebo condition was compared to that for eachof the three treatments (ginkgo, ginkgo+PC (phosphatidylcholine),ginkgo+PS (phosphatidylserine)). To ensure the overall Type I errorprotection level only those planned comparisons associated with measuresthat generated a significant main effect or interaction effect on theinitial ANOVA are reported. Furthermore, all testing was two-tailed,comparisons were strictly planned prior to the study, were restricted tothe number of conditions minus one at each time-point, and onlyprobabilities associated with these pre-planned comparisons werecalculated.

RESULTS Cognitive Assessment

Baseline scores

Prior to analysis of change from baseline data, mean pre-dose rawbaseline scores for all four conditions (placebo, ginkgo, ginkgo+PC,ginkgo+PS) for each outcome (single task outcomes, cognitive factorscores, and mood scale scores) were subjected to a one-way,repeated-measures ANOVA followed, for measures generating a significantresult, by planned comparisons as per the cognitive outcome data.Several single task outcomes generated significant pre-dose baselinedifferences on the planned comparisons. Prior to ingestion of the daystreatment participants in the ginkgo+PS condition performedsignificantly less accurately [t (81)=2.32, p=0.022] and more slowly [t(81)=2.75, p=0.007] than placebo on the Digit vigilance task. The samecondition performed significantly slower on the Word recognition task [t(81)=2.11, p=0.036]. No other planned comparisons proved significant forany other measure.

Individual Task Outcome Measures

Effects and performance data on the individual task outcome measuresfrom the CDR battery are shown in FIGS. 1, 3 and 5. Results of plannedcomparisons of individual task outcomes that generated a significantresult on the initial ANOVA (statistic not reported) are described inrelationship to the overall factor to which they contribute below. Meanbaseline and change from baseline scores (with standard errors) arepresented. Tasks are displayed in order of completion, with a graphicalrepresentation of measures generating significant differences on theinitial ANOVA and subsequent planned comparisons (*, p=0.05; **, p=0.01;***, p=0.005, *****, p=0.0005 compared to placebo).

Cognitive Factor Outcome Measures

Effects of the treatments on the primary outcome cognitive factorsderived from the CDR battery outcomes are shown in FIGS. 2 and 4. Meanbaseline and change from baseline scores (with standard errors) arepresented, with a graphical representation of the factors generatingsignificant differences on the initial ANOVA and subsequent plannedcomparisons (*, p=0.05; **, p=0.01; ***, p=0.005, ****, p=0.001 comparedto placebo).

Speed of Attention Factor (FIG. 1)

Whilst there was no significant difference on the primary outcomefactor, a single component task outcome (digit vigilance reaction time)generated significant differences on the initial ANOVA and subsequentplanned comparisons. Both ginkgo [t (243)=2.45, p=0.015 ] and ginkgo+PS[t (243)=2.25, p=0.026 ] performed significantly faster than placebo at2.5 hours post-dose with the latter condition also performing faster at6 hours [t (243)=2.5, p=0.013].

Accuracy of Attention Factor (FIG. 1)

Whilst there was no significant difference on the primary outcomefactor, two single component task outcome (digit vigilance reactiontime) generated significant differences on the initial ANOVA andsubsequent planned comparisons. Accuracy of performing the Digitvigilance task was significantly improved for the ginkgo+PS condition atboth 1 hour [t (243)=2.58, p=0.011] and 4 hours [t (243)=2.14, p=0.034 ]post-dose. In contrast to this all three doses evinced decrements in theaccuracy of performing the Choice reaction time task with this effectbeing evident for ginkgo at 2.5 hours [t (243)=2.46, p=0.015 ], 4 hours[t (243)=2.66,p=0.009] and 6 hours [t (243)=2.56, p=0.011 ] post-dose,for ginkgo+PC at 4 hours post-dose [t (243)=2.86, p=0.005], and forginkgo+PS at 4 hours [t (243)=3.45, p=0.001 ] and 6 hours [t (243)=2.46,p=0.015 ] post-dose.

Speed of Memory Factor (FIGS. 2 and 3)

The initial ANOVA showed that there was a significant main effect of thetreatment on the Speed of Memory factor [F (3, 405)=15.76, p<0.001].Planned comparisons showed that performance was enhanced at all timepoints following ginkgo+PS (1 hour [t (243)=2.58, p=0.011 ], 2.5 hours[t (243)=3.19, p=0.002 ], 4 hours [t (243)=3, p=0.003] and 6 hours [t(243)=4, p<0.001] post-dose). In contrast to this, performance wassignificantly slowed for the ginkgo+PC condition at 4 hours post-dose [t(243)=3, p<0.003].

Reference to the ANOVAS of the single outcomes contributing to thisfactor showed that performance was significantly modulated on all fourtasks. Planned comparisons showed that following ginkgo+PS performancewas faster on: the Spatial memory task at 6 hours [t (243)=2.23,p<0.027], with trends towards the same at 2.5 hours [t (243)=1.8,p=0.071],) and 4 hours [t (243)=1.92, p=0.056]; the Numeric workingmemory task at 4 hours [t (243)=3.29, p=0.001] and 6 hours [t(243)=2.944, p=0.004]; the Word recognition task at 1 hour [t (243)=2.2,p=0.028], 2.5 hours [t (243) =2.75, p=0.006], and 4 hours [t (243)=2.77,p=0.006], with a trend towards the same at 6 hours post-dose [t(243)=1.91, p=0.057]; and the Picture recognition task at 6 hours [t(243)=3.12, p=0.002], with trends towards the same at 1 hour [t(243)=1.75, p=0.082] and 2.5 hours [t (243)=1.82, p=0.071].

In contrast to these marked improvements both of the other conditionswere associated with the occasional decrement, with ginkgo evincingslowed performance on the Spatial memory task at 6 hours [t (243)=2.56,p=0.011] ,and the Picture recognition task at 4 hours [t (243)=2.25,p=0.026], and ginkgo+PC evincing slowed performance on the Numericworking memory task at 4 hours [t (243)=2.15, p=0.033] and the Picturerecognition task at 4 hours post-dose [t (243)=3.8, p<0.001].

Quality of Memory Measure (FIGS. 4 and 5)

The initial ANOVA showed that there was a significant main effect oftreatment on the global Quality of Memory measure [F (3, 405)=3.33,p=0.02]. Planned comparisons showed that ginkgo+PS resulted in improvedchange from baseline performance at 2.5 hours [t (243)=2.35, p=0.02] and4 hours [t (243)=2.46, p=0.015] with a trend towards the same at 1 hour[t (243) =1.78, p =0.077] post-dose. Performance was also enhanced forginkgo+PC at 2.5 hours [t (243)=2.67, p=0.008].

Reference to the contributing single task outcomes showed thatperformance was only significantly improved on one individual taskoutcome task, with ginkgo+PS outperforming placebo at 1 hour [t(243)=2.39, p=0.018], 2.5 hours [t (243)=2.24, p=0.027] and 4 hours [t(243)=2.43, p=0.016] on the Picture recognition task.

Secondary Memory Factor

The initial ANOVA suggested that this factor was not significantlyaffected by the treatment.

Working Memory Factor

The initial ANOVA suggested that this factor was not significantlyaffected by the treatment.

Serial 7s and Serial 3s Subtraction Tasks

The initial ANOVA suggested that these tasks were not significantlyaffected by the treatments.

Mood assessment

The changes from baseline scores for the three mood factors (alert,content, calm) are evaluated. FIG. 5 illustrates the effects of thetreatments on the mood factor ‘calm’ derived from the Bond-Lader moodscales. Mean baseline and change from baseline scores (with standarderrors) are presented, with a graphical representation of the factorthat generated significant differences on the initial ANOVA andsubsequent planned comparisons (*, p=0.05; **, p=0.01; ***, p=0.005,****, p=0.001,*****, p=0.0005 compared to placebo).

Bond-Lader Mood Scales (cf. FIG. 5)

The initial ANOVA suggested that there was only a main effect oftreatment on the “Calm” factor derived from the visual analogue scales[F (3, 405)=2.95, p<0.032]. Planned comparisons revealed that all threetreatments resulted in enhanced “calmness” in comparison to placebo.This effect was evident for ginkgo at 1 hour [t (243)=3.05, p=0.003] and4 hours [t (243)=3.02, p=0.003], ginkgo+PC at 1 hour [t (243)=2.87,p=0.005], and ginkgo+PS at 1 hour [t (243)=2.1, p=0.036] and 6 hours [t(243)=1.99, p=0.048] post-dose.

Summary of the Effects

It has been found that the ginkgo phosphatidylserine complex usedaccording to the present invention has an outstanding higher effectivitycompared with the other tested species, i.e. not complexed ginkgo orginkgo phosphatidylcholine complex, regarding Quality of Memory, PictureRecognition Accuracy, Speed of Memory, Timed Memory Tasks and themajority of the tasks concerning attention.

1-22. (canceled)
 23. A method for the enhancement of cognitive functionand mental fatigue, comprising: administering to a subject in needthereof Ginkgo complexed with a phopholipid containing lo to 50% ofphosphatidylserine.
 24. The method according to claim 23 wherein thephospholipid contains from 20 to 40% of phosphatidylserine.
 25. Themethod according to claim 23 wherein the phospholipid contains 20% ofphospatidylserine.
 26. The method according to claim 23, wherein theGinkgo is derived from the plant Ginkgo biloba, extracts thereof and/orone or more principal active substances thereof.
 27. The methodaccording to claim 26, wherein one of the principal active substances isbilobalide.
 28. The method according to claim 26, characterized in thatthe Ginkgo extract is used containing at least about 20% Ginkgo flavoneglycosides and about 2 to about 10% terpene lactones.
 29. The methodaccording to claim 23, wherein the ratio between Ginkgo and thephosphatidylserine used to prepare the complex is about 1:1.
 30. Themethod according to claim 23, wherein the medicament or dietarysupplement is administered in the form of tablets, granules, powders,capsules, syrups, solutions, suspensions, dragees, gels, injections ordrops.
 31. The method according to claim 23, wherein the medicament ordietary supplement is formulated for oral administration.
 32. The methodaccording to claim 23, wherein the Ginkgo phosphatidylserine complexcontained in the medicament or dietary supplement is to be administeredin an amount of about 20 to about 240 mg per day, particularly about 60to about 120 mg per day.
 33. The method according to claim 23, whereinthe medicament or dietary supplement additionally contains apharmaceutically acceptable amount of at least one additive selectedfrom the group comprising minerals, vitamins, sweeteners, flavors,pharmaceutically acceptable carriers, auxiliary and binder agents,excipients and mixtures thereof.
 34. The method according to claim 33,wherein the additive is selected from vitamins, minerals and mixturesthereof, particularly selected from calcium, fluorine, phosphorus,copper, potassium, manganese, magnesium selenium, zinc and iron, VitaminA, Vitamins B1, B2 and B12, Vitamin C, Vitamin D2, nicotinamide, calciumpantotenate, rutoside and Vitamin E.
 35. A method for the enhancement ofcognitive function and mental fatigue by improving the speed of memoryand memory quality, by counteracting cognitive fatigue in normal,healthy persons or by preventing deterioration of the speed of memory inpeople with decreased cognitive functions, comprising administering to asubject in need thereof an effective amount of a Ginkgo complexed withphosphatidylserine.
 36. A method for the treatment and prevention of adiesease related with the reduction of cognitive function and mentalfatigue, comprising administering to a subject in need thereof aneffective amount of a Ginkgo complexed with phosphatidylserine.
 37. Themethod according to claim 36 wherein the disease is Dementia.
 38. Themethod according to claim 37 wherein the disease is Alzheimer's Disease.39. The method according to claim 36 wherein the medicament or dietarysupplement additionally contains a pharmaceutically acceptable amount ofat least one additive selected from the group comprising vitamins,minerals, sweeteners, flavors, pharmaceutically acceptable carriers,auxiliary and binder agents, excipients and mixtures thereof.
 40. Themethod according to claim 36 in combination with a pharmaceuticalcompound used for the treatment and prevention of the disease to betreated related with the reduction of cognitive function and mentalfatigue.
 41. The method according to claim 40, wherein thepharmaceutical compound is an acetylcholinesterase inhibitor.
 42. Themethod according to claim 40, wherein the additionally active compoundis complexed grape seed extract.
 43. A pharmaceutical or dietarycomposition comprising Ginkgo complex and at least one vitamin and apharmaceutically or dietarily acceptable carrier.
 44. A complex of anextract of Ginkgo with a phosphatidylserine of formula

wherein R and R¹ each independently represent an acyl moiety selectedfrom the fatty acids consisting of palmitic acid, oleic acid, linoleicacid, stearic acid.
 45. A complex according to claim 44, which comprisesfrom 15 to 25% of saturated fatty acids, from 5 to 15% ofmono-unsaturated fatty acids and from 60 to 80% of polyunsaturated fattyacids, based on the total acids.